Regulation National Market System (Reg NMS) was designed to equalize the playing field for participants in the U.S. stock market, ensuring fair access to trading opportunities. However, the actual outcome was quite different; it inadvertently fostered a system of inequality. A select group of insiders, equipped with advanced technology and speed advantages, gained the upper hand in market transactions.

These insiders had the ability to observe market movements before others and acted on that information to execute trades, thus undermining the very fairness Reg NMS aimed to promote. This situation created a significant disparity between those with access to high-speed trading resources and the average investor, leading to a more inequitable market environment as described in Michael Lewis's book, "Flash Boys."